Heterodyne optical network analysis (HONA) is an interferometric measurement technique for characterizing the linear optical properties of a device under test (DUT) over a desired spectral range. Commercially available HONA instruments are employed to characterize telecommunications-related components, such as fiber Bragg gratings and arrayed waveguide gratings.
Often, these optical components have more than one port that needs to be characterized. In conventional HONA instruments, only one measurement channel is available to characterize a DUT and therefore each port of the DUT must be characterized serially, which is a time consuming process. While it is possible to build a parallel HONA system using multiple cascaded optical splitters that distribute the local oscillator signal of the HONA to multiple receivers, the distribution of the local oscillator signal to each of the receivers using cascaded optical splitters is complicated, expensive, and lossy.